MHB Deriving a Vector Expression from Given Direction

[Drain Brain]

How can you derive an expression from the given direction defined by dx=2dy=-2dz. This is just a part of a problem that I'am solving. I have no idea how to get a vector expression using the given info. please help. Thanks!

by the way I'm trying to find the directional derivative of a certain scalar function in the direction given above. By I don't know how to get a vector representayion of the given direction. Please help me!

 

[paulmdrdo1]

is that possible? use derivative.

 

[Drain Brain]

What? I Know that I would use partial derivative here. But what I need help with is finding the vector representation of the given direction. Please anybody knows how to do it tell me. Thanks.!

 

[Drain Brain]

Hey guys, do you have any idea on how to do this? I want to know it so badly. Please give me an insight.